A study estimated that 4.3 million Americans between 65 and 83 experience dry eyes symptoms (Schein et al., 1997). With population aging, more and more people are likely to be affected. Most of the time, this condition is caused by a dysfunction of Meibomian Glands. Dry eyes are very painful and can spoil the quality of life of patients. Itching, burning eyes, blurred vision and increased risk of infection are part of their everyday life. Air conditioning, computer work, wind and dust are contributory factors that trigger the painful symptoms. The condition may be critical in some office or outside workers.
The secretion produced by Meibomian Glands is an oily liquid made of wax and sterols esters, fatty acids and fatty alcohols (Knop et al., 2011; Butovich, 2011). The secretion forms a 0.1 μm lipid film on the cornea, over the tears (Korb et al., 1994; Norn, 1979). Its functions are to provide a surfactant on the eye surface, to reduce tear evaporation, and to prevent contamination of the eye by other substances or bacteria (Mudgil and Millar, 2011; Bron et al., 2004; Driver and Lemp, 1996). Due to its variety of chemical components, the melting point of Meibomian oil is a range. Bron et al. (2004) summarized five previous studies and proposed the melting temperature ranging from 19.5 to 32.9° C.±0.9° C. for normal glands. It is also stated that the range can extend up to 40° C. in the “presence of keratinized epithelial debris within the expressed material” (Bron et al., 2004; Terada et al., 2004; Gutgesell et al., 1982; Jester et al., 1981). The viscosity of the secretion is within the 9.7-19.5 Pa·s range at 30° C. (which is comparable to honey). The secretion exhibits shear thinning non-Newtonian properties, its viscosity decreases (down to 0.1 mPa·s) when a shearing force is applied (similar to the behaviour of ketchup when a bottle is squeezed). This behaviour makes it easier to release the meibum during blinking (which has the effect of “milking” the glands. In case of Meibomian Gland Dysfunction (MGD) or chalazion, viscosity can increase significantly (69.9 Pa·s, measured at 70° C.) (Knop et al., 2011) preventing the release of secretion.
The two main causes of MGD are the hyperkeratinisation of the ducts and the degeneration of the acini cells (Knop et al., 2011). Keratin fibres are produced to rigidify the excretory duct at the border of the eyelid. In case of hyperkeratinisation, the extemal duct diameter is reduced or completely blocked. The pressure increases in the gland and atrophies the acini cells. The second cause is the degeneration of the acini cells. Melbum synthesis is degraded and the quantity and the quality of secretion decreases. The liquid is more viscous, often compared to toothpaste (Tomlinson et al., 2011), and loses some of its surfactant properties. These two phenomena lead to the obstruction of the glands. The process can be summarized as several vicious circles (Knop et al., 2011).
The consequence of MGD is a shortage of oil in the eye surface. This results in tears evaporating 30% quicker than an unaffected eye (Bron et al., 2004), and an uneven optical surface of the eye. For the patient this translates into: bad vision, difficult blinking, dry eye, increased risk of infection, irritation, itching, and the inability to wear contact lenses (Driver and Lemp., 1996)
It is unclear what proportion of the entire population is affected by gland dysfunction. Whilst many studies have been carried out, they target different groups of people or use different criteria, which prevents accurate comparisons and precludes definite conclusions being drawn (Schaumberg et al., 2011). As an example, the prevalence of MGD ranges from 20% in a British study (Ong and Larke, 1990) to 60% in a Japanese one (Shimazaki et al., 1995). Notwithstanding this, numerous studies establish aging as the main factor for MGD. It has been recognised for a long time that MGD probability increases with age and MGD is more common after 50 years of age (Hykin and Bron, 1992; Hom et al., 1990; Den et al., 2006). Other factors, including medicines and other external potential causes were studied, but correlations are hard to establish (Schaumberg et al., 2011).
For the most part, existing dry eye treatments are home-based. The market offers a wide array of heat masks, pads, bags and compresses. These solutions are focussed on heating and/or moisturising the eyelids. The devices usually have to be placed in a microwave oven to accumulate heat. Patients can also access a range of goggles that prevent tear evaporation during the night. Other treatments include artificial tears and special “shampoo” or gels to scrub the eyelids. Cotton buds can be used to clean the lid margins. A few antibiotics exist but they have undesirable side effects.
A non-limiting list of existing treatments include:
The Lipi flow thermal pulsation treatment produced by TearScience® is a machine composed of an ocular component and a hand held control system. The ocular component is consisting of a lid warmer providing heat (41° C. to 43° C.) an eye cup that compresses the eye lid to express the meibomlan gland.
There is also the I Heat portable warm compress mask. This is an eye mask that comes with a disposable warming unit that is activated by the user.
Another mask is the Fire & Ice mask by Rhein Medical the mask is placed in the microwave for under 15 secs and then the user can use it for the warm compress it can also be used for cold compress.
Another treatment is by the use of the Blephasteam®, a device based from the studies of DR J. R. Fuller. It is a goggle that gives off moisture and heat as a result of the steam it produces.
A further treatment is simply a warm compress self-treatment, carried out by patients according to the advice of their ophthalmologists. This typically involves warm compress achieved by the traditional method of using hot cloth followed by a massage using the finger to be done on a regular basis.
The Infrared warm compression device (IWCD, Eye Hot, Cept Co, Tokyo, Japan) is an electrically powered device composed of two eye patches each incorporating 19 LEDs emitting 850 to 1050 nm.
A non-limiting list of examples of patent or design applications relating to heat or massage treatments is given below: GILBARD et al, ‘Cleanser composition and methods for using the same’, US 2010/0285155; LIU, H. C., ‘Eyes massage device’, US 2006/0206041; NIELSEN, M. J., ‘Massaging tool and method for lower-eyelids and zygomatic skin’, U.S. Pat. No. 4,554,911; PARSLOE, C., ‘Massage apparatus and method of use’, US 2012/0165708; YEE, R. W., ‘Method and apparatus for preventing and treating eyelid problems’, U.S. Pat. No. 7,069,084; BREEN, E. V., ‘Compositions and methods for maintaining eyelid hygiene’, US 2005/0220742; KNOP et al, ‘The International workship on meibomian gland dysfunction: report of the subcommittee on anatomy, physiology, and pathophysiology of the meibomian gland’, IOVS 2011; SMITH, et al, ‘Device for stimulating the meibomian glands of the eyelid’, U.S. D645,565; KORB, et al, ‘Method and apparatus for treating meibomian gland dysfunction’, U.S. Pat. No. 8,025,689; STAHL, N. O., ‘Ocular massage device’, U.S. Pat. No. 4,303,063; KORB, et al., ‘Outer eyelid heat and pressure treatment for treating meibomian gland dysfunction’, U.S. Pat. No. 7,981,147; KORB. et al., ‘System for inner eyelid heat and pressure treatment for treating meibomian gland dysfunction’, U.S. Pat. No. 8,128,673; MAY, F. H., ‘Eye-massage machine’, forming part of 793,004 (1905).
Thus it can be seen that the provision of new and effective treatments for dry eye would provide a contribution to the art. Furthermore eye massage has a number of other potential cosmetic and therapeutic benefits. Therefore the provision of an eye massage device which was simple and convenient to use would also be highly beneficial.